全文获取类型
收费全文 | 20501篇 |
免费 | 2694篇 |
国内免费 | 1491篇 |
专业分类
化学 | 1405篇 |
晶体学 | 145篇 |
力学 | 3389篇 |
综合类 | 388篇 |
数学 | 14130篇 |
物理学 | 5229篇 |
出版年
2024年 | 33篇 |
2023年 | 181篇 |
2022年 | 262篇 |
2021年 | 319篇 |
2020年 | 497篇 |
2019年 | 452篇 |
2018年 | 444篇 |
2017年 | 613篇 |
2016年 | 623篇 |
2015年 | 446篇 |
2014年 | 914篇 |
2013年 | 1497篇 |
2012年 | 943篇 |
2011年 | 1201篇 |
2010年 | 1024篇 |
2009年 | 1203篇 |
2008年 | 1345篇 |
2007年 | 1344篇 |
2006年 | 1256篇 |
2005年 | 1202篇 |
2004年 | 980篇 |
2003年 | 1032篇 |
2002年 | 946篇 |
2001年 | 764篇 |
2000年 | 738篇 |
1999年 | 705篇 |
1998年 | 599篇 |
1997年 | 536篇 |
1996年 | 368篇 |
1995年 | 306篇 |
1994年 | 255篇 |
1993年 | 234篇 |
1992年 | 181篇 |
1991年 | 148篇 |
1990年 | 137篇 |
1989年 | 74篇 |
1988年 | 88篇 |
1987年 | 81篇 |
1986年 | 77篇 |
1985年 | 87篇 |
1984年 | 87篇 |
1983年 | 42篇 |
1982年 | 66篇 |
1981年 | 68篇 |
1980年 | 49篇 |
1979年 | 44篇 |
1978年 | 59篇 |
1977年 | 41篇 |
1976年 | 31篇 |
1974年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
《Mendeleev Communications》2022,32(4):507-509
We report on the synthesis of new Ru(bpy)2(phen) catalyst for the oscillatory Belousov–Zhabotinsky chemical reaction and on the preparation of novel Ru(bpy)2(phen)-based self-oscillating gels. The synthesized gels exhibit high-amplitude autonomous mechanical oscillations when the Belousov–Zhabotinsky reaction proceeds inside these gels 相似文献
3.
Marcus Carlsson 《Expositiones Mathematicae》2021,39(1):149-157
von Neumann’s inequality in matrix theory refers to the fact that the Frobenius scalar product of two matrices is less than or equal to the scalar product of the respective singular values. Moreover, equality can only happen if the two matrices share a joint set of singular vectors, and this latter part is hard to find in the literature. We extend these facts to the separable Hilbert space setting, and provide a self-contained proof of the “latter part”. 相似文献
4.
In this article, we construct and analyze a residual-based a posteriori error estimator for a quadratic finite volume method (FVM) for solving nonlinear elliptic partial differential equations with homogeneous Dirichlet boundary conditions. We shall prove that the a posteriori error estimator yields the global upper and local lower bounds for the norm error of the FVM. So that the a posteriori error estimator is equivalent to the true error in a certain sense. Numerical experiments are performed to illustrate the theoretical results. 相似文献
5.
6.
In this paper, the deformation of the Heisenberg algebra, consistent with both the generalized uncertainty principle and doubly special relativity, has been analyzed. It has been observed that, though this algebra can give rise to fractional derivative terms in the corresponding quantum mechanical Hamiltonian, a formal meaning can be given to them by using the theory of harmonic extensions of function. Depending on this argument, the expression of the propagator of the path integral corresponding to the deformed Heisenberg algebra, has been obtained. In particular, the consistent expression of the one dimensional free particle propagator has been evaluated explicitly. With this propagator in hand, it has been shown that, even in free particle case, normal generalized uncertainty principle and doubly special relativity show very much different result. 相似文献
7.
Bobby Wilson 《偏微分方程通讯》2015,40(8):1521-1542
This article explores the questions of long time orbital stability in high order Sobolev norms of plane wave solutions to the NLSE in the defocusing case. 相似文献
8.
Recent Progress in the $L_p$ Theory for Elliptic and Parabolic Equations with Discontinuous Coefficients
下载免费PDF全文
![点击此处可从《分析论及其应用》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hongjie Dong 《分析论及其应用》2020,36(2):161-199
In this paper, we review some results over the last 10-15 years on elliptic and parabolic equations with discontinuous coefficients. We begin with an approach given by N. V. Krylov to parabolic equations in the whole space with $\rm{VMO}_x$ coefficients. We then discuss some subsequent development including elliptic and parabolic equations with coefficients which are allowed to be merely measurable in one or two space directions, weighted $L_p$estimates with Muckenhoupt ($A_p$) weights, non-local elliptic and parabolic equations, as well as fully nonlinear elliptic and parabolic equations. 相似文献
9.
This paper deals with the Cauchy–Dirichlet problem for the fractional Cahn–Hilliard equation. The main results consist of global (in time) existence of weak solutions, characterization of parabolic smoothing effects (implying under proper condition eventual boundedness of trajectories), and convergence of each solution to a (single) equilibrium. In particular, to prove the convergence result, a variant of the so-called ?ojasiewicz–Simon inequality is provided for the fractional Dirichlet Laplacian and (possibly) non-analytic (but ) nonlinearities. 相似文献
10.
M.A. Tawhid 《Journal of Optimization Theory and Applications》2002,113(1):149-164
In this paper, we give some sufficient conditions for the local uniqueness of solutions to nonsmooth variational inequalities where the underlying functions are H-differentiable and the underlying set is a closed convex set/polyhedral set/box/polyhedral cone. We show how the solution of a linearized variational inequality is related to the solution of the variational inequality. These results extend/unify various similar results proved for C
1 and locally Lipschitzian variational inequality problems. When specialized to the nonlinear complementarity problem, our results extend/unify those of C
2 and C
1 nonlinear complementarity problems. 相似文献